This invention relates to a method and apparatus for producing carbide products, such as silicon carbide. In another aspect, the invention relates to the composition of such carbide products.
Various carbide powders, such as silicon carbide, are useful as advanced ceramic materials in the fabrication of highly stressed, wear resistant ceramic parts, such as those employed in heat engines, turbo-charger rotors and heat exchangers. Powders which are used to make such parts must meet stringent particle size (i.e. submicron) and purity requirements. New synthesis methods currently being researched, involving plasma and laser heating of gaseous reactants, for example, are effective in producing submicron, high purity carbide powders, but employ expensive equipment with high energy demands. Thus, these methods may not be practical for economical, large scale synthesis. A more conventional method involves electrically heating a mixture of solid carbon and silicon dioxide. Large chunks of silicon carbide are produced which must be reduced in size by mechanical grinding. Such grinding adds undesirable metal impurities and requires a significant amount of additional energy.